Ingrid Eckerman* reports that documents discovered in
the Bhopal plant as well as others traced later show that UCC had conducted
experiments on animals and knew ell the effects of MIC, both in the short and
long term. They banned publication of the test results on rats which suggests
that they were horrific. Had they shown no harm then I am sure that UCC would
have emblazoned them on banners.
She
writes, “ experiments had shown that
animals exposed to MIC vapours died almost instantaneously. The vapours destroyed
the respiratory system with lightening speed, caused irreversible blindness and
burnt the pigment of the skin.”
Yet
after the incident, the plant’s own medical doctor insisted that MIC was only
an irritant and not life threatening.
Since
1963, studies on MIC have concluded:
·
it
is the most toxic of the isocyanate family,
·
it
is highly toxic both from breathing and skin penetration,
·
it
is highly toxic and a hazard to life by inhalation,
·
it
is an irritant to humans at very low concentrations.
UCC
manuals also describe a runaway reaction scenario when MIC is contaminated by
water or some metals. Only stainless steel appears to be a safe container. So
management could never deny that they knew the danger or the possible results
of a leak.
The Bhopal
plant was designed to be a sister to the one in Institute, West Virginia but
almost before it was built the market for Sevin was falling and so the standard
of the factory was reduced.
Again Ingrid Eckerman* writes: “Between 1980
and 84, the UCC plant in Institute, West Virginia, USA had 67 leaks of MIC –
but did not disclose this to the local population.” That, surely, should have warned
UCC that safety was of paramount importance – maybe that was why they wanted to
build this plant in India?
Lee Sustar has written in Counterpunch*, “The West Virginia operation had computerized
monitors of valves and storage tanks; the Bhopal facility had only manual
gauges. Operators in West Virginia had to undergo months of safety training; in
Bhopal, such training was minimal. A loud siren at the U.S. plant was designed
to warn workers and the community of any leaks of toxic chemicals; the Bhopal
operation’s warning system was dismantled and replaced because frequent spills
had triggered alarms so often.”
The
other main difference was the more streamlined production process in Institute
which meant that the MIC was not stored for such long periods.
As
demand fell, standards were reduced further with staff reductions and the use
of unqualified staff. Even the Indian trade union was concerned and wrote to
management.
Apart
from the MIC itself, when it reacts as it did that night, many other toxic and
non-toxic gasses are produced so the cloud that engulfed Bhopal was a lethal
cocktail. UCC and, since 2001, Dow Chemical, has not released a full list of
what could have been included. It may be that they are uncertain, of course! But,
if so, they could at least give a list of what could be present. That would have
helped the doctors dealing with the immediate aftermath as well as assessing
the long term implications for treatment now.
I
will conclude this post with some of the known technical data about MIC with
links to my sources:
Methyloisocyanate
Methyl isocyanate (MIC)
is extremely toxic. The threshold limit value set by the
American Conference on Government Industrial Hygienists is 0.02 ppm.
MIC is toxic by inhalation, ingestion and contact in quantities as low as 0.4 ppm.
Exposure symptoms includes coughing, chest pain, dyspnea,
asthma,
irritation of the eyes, nose and throat, as well as skin damage. Higher levels
of exposure, over 21 ppm, can result in pulmonary or lung edema,
emphysema
and hemorrhages, bronchial pneumonia
and death. Although the odor of methyl isocyanate cannot be detected at 5 ppm
by most people, its potent lachrymal
properties provide an excellent warning of its presence (at a concentration of
2–4 parts per million (ppm) subject's eyes are irritated, while at 21 ppm,
subjects could not tolerate the presence of methyl isocyanate in air).[14]
Proper care must be
taken to store methyl isocyanate because of its ease of exothermically
polymerizing (see Reactions)
and its similar sensitivity to water. Only stainless steel or glass containers
may be safely used; the MIC must be stored at temperatures below 40 °C
(104 °F) and preferably at 4 °C (39°F).
Other
links:
USA
Environmental Protection Agency - http://www.epa.gov/ttnatw01/hlthef/methylis.html
Cameo
Chemicals - http://cameochemicals.noaa.gov/chemical/1112
Diamond
|
Hazard
|
Value
|
Description
|
|||||||||
|
Health
|
4
|
Can be
lethal.
|
|||||||||
Flammability
|
3
|
Can be
ignited under almost all ambient temperature conditions.
|
||||||||||
Instability
|
2
|
Readily
undergoes violent chemical changes at elevated temperatures and pressures.
|
||||||||||
Special
|
Reacts
violently or explosively with water.
|
A
colourless low-boiling liquid (39°C) that is denser than water. Flash point is
less than 20° F. Very toxic by inhalation. Can be absorbed through the skin.
Has a sharp odour, but the sense of smell cannot be relied upon to warn of the
presence of vapours at low concentrations.
Rate of onset: Immediate
Persistence: Minutes to hours
In summary,
humans exposed acutely by inhalation to MIC may experience long term (as well
as immediate) damage to pulmonary and extrapulmonary systems. The lung is
probably the critical target organ for long term effects from acute exposure,
although adverse effects on other organs (e.g., eye, reproductive, and
gastrointestinal) also exist. The late responses to the acute exposure suggest
an immunological component, which could involve several systems including lung,
eye, liver, and kidney. The chemical identity of the ultimate toxicant is
unknown and may be more than one compound
*
The
Bhopal Saga by Ingrid Eckerman
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